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butterweed

roundleaf ragwort, running groundsel

Habit Annuals or biennials, 20–70+ cm; fibrous-rooted (caudices relatively short, weak). Perennials, 20–50+ cm; stoloniferous and rhizomatous (rhizomes horizontal to suberect).
Stems

1 (striated, frequently hollow, often pink- to purple-tinged), glabrous or leaf axils sparsely tomentose.

1 or multiple, loosely clustered, usually glabrous, sometimes tomentose proximally and in leaf axils.

Basal leaves

(and proximal cauline) obscurely petiolate;

blades obovate to oblanceolate, sometimes lyrate (lateral lobes to 5 pairs, terminal lobes larger than laterals), 50–150+ × 10–30+ mm, bases tapering, ultimate margins crenate to irregularly undulate.

(and proximal cauline) petiolate;

blades orbiculate, ovate, or obovate, 40–100+ × 20–80+ mm, bases tapering, rounded, or abruptly contracted, margins crenate, dentate, or serrate.

Cauline leaves

gradually reduced (weakly clasping, similar to basal).

gradually reduced (sessile, clasping; pinnatisect or sublyrate).

Peduncles

bracteate, glabrous or bases tomentose.

bracteate, glabrous or proximally tomentose.

Ray florets

(8–)13;

corolla laminae 7–9 mm.

8–13(–21);

corolla laminae 7–10 mm.

Disc florets

35–50+;

corolla tubes 2.5–3.5 mm, limbs 2–3 mm.

40–50+;

corolla tubes 2–3 mm, limbs 2–3 mm.

Phyllaries

(13–)21, green, 5–7 mm, glabrous.

13 or 21, green (tips sometimes reddish), 3–6 mm, glabrous or floccose-tomentose proximally.

Calyculi

conspicuous (bractlets 2.5–4 mm).

conspicuous.

Heads

8–30+ in umbelliform or cymiform arrays (robust plants with multiple arrays).

6–15+ in open or congested, corymbiform arrays.

Cypselae

1–1.5 mm, sparsely hirtellous on ribs or glabrous;

pappi 3–4 mm.

1–1.5 mm, glabrous or hirsute on ribs;

pappi 3–6 mm.

2n

= 46.

= 44, 88, 90.

Packera glabella

Packera obovata

Phenology Flowering (Feb–)mid Mar–late May. Flowering late Feb–Apr (south), early Apr–early Jun (north).
Habitat Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields Meadows in deciduous woodlands, wet ditches, stream banks, rocky hillsides
Elevation 0–600 m (0–2000 ft) 0–2500 m (0–8200 ft)
Distribution
from FNA
AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; NC; NE; OH; OK; SC; TN; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; FL; GA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NH; NJ; NM; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WV; ON; QC; Mexico (Coahuila)
[WildflowerSearch map]
[BONAP county map]
Discussion

Packera glabella is common and almost weedy in wet, partially shaded places. The hollow, striated stems of P. glabella are distinctive.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Packera obovata forms relatively large, stoloniferous colonies in wet sites.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 588. FNA vol. 20, p. 594.
Parent taxa Asteraceae > tribe Senecioneae > Packera Asteraceae > tribe Senecioneae > Packera
Sibling taxa
P. anonyma, P. antennariifolia, P. aurea, P. bernardina, P. bolanderi, P. breweri, P. cana, P. cardamine, P. castoreus, P. clevelandii, P. contermina, P. crocata, P. cymbalaria, P. cynthioides, P. debilis, P. dimorphophylla, P. eurycephala, P. fendleri, P. flettii, P. franciscana, P. ganderi, P. greenei, P. hartiana, P. hesperia, P. hyperborealis, P. indecora, P. ionophylla, P. layneae, P. macounii, P. malmstenii, P. millefolium, P. millelobata, P. multilobata, P. musiniensis, P. neomexicana, P. obovata, P. ogotorukensis, P. pauciflora, P. paupercula, P. plattensis, P. porteri, P. pseudaurea, P. quercetorum, P. sanguisorboides, P. schweinitziana, P. spellenbergii, P. streptanthifolia, P. subnuda, P. tampicana, P. texensis, P. tomentosa, P. tridenticulata, P. werneriifolia
P. anonyma, P. antennariifolia, P. aurea, P. bernardina, P. bolanderi, P. breweri, P. cana, P. cardamine, P. castoreus, P. clevelandii, P. contermina, P. crocata, P. cymbalaria, P. cynthioides, P. debilis, P. dimorphophylla, P. eurycephala, P. fendleri, P. flettii, P. franciscana, P. ganderi, P. glabella, P. greenei, P. hartiana, P. hesperia, P. hyperborealis, P. indecora, P. ionophylla, P. layneae, P. macounii, P. malmstenii, P. millefolium, P. millelobata, P. multilobata, P. musiniensis, P. neomexicana, P. ogotorukensis, P. pauciflora, P. paupercula, P. plattensis, P. porteri, P. pseudaurea, P. quercetorum, P. sanguisorboides, P. schweinitziana, P. spellenbergii, P. streptanthifolia, P. subnuda, P. tampicana, P. texensis, P. tomentosa, P. tridenticulata, P. werneriifolia
Synonyms Senecio glabellus, Senecio carolinianus, Senecio densiflorus, Senecio lobatus, Senecio lyratus, Senecio mississipianus Senecio obovatus, Senecio aureus var. obovatus, Senecio elliottii, Senecio elongatus, Senecio rotundus
Name authority (Poiret) C. Jeffrey: Kew Bull. 47: 101. (1992) (Muhlenberg ex Willdenow) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981)
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